Breast diseases and the internist.

Benign breast disease affects almost all women, although only one out of 11 will eventually develop breast cancer. Fibrocystic disease or benign breast mastopathies have been associated with an increased propensity to progress to malignancy. However, the increased relative risk for women with benign breast disease developing breast cancer appears to be associated with proliferative benign disease in association with atypia. Their cumulative risk may be as high as 30%. These women represent 3-5% of women with benign disease. They clearly warrant more careful screening and follow-up. The etiology of benign breast mastopathies is unknown, but its incidence and relationship to hormonal events suggests that many of the histologic entities represent an endocrine response. Many hormonal manipulations have been shown to decrease mastodynia and reduce the incidence of breast aspirations and biopsies. However, these and other therapeutic interventions have not been shown to reduce the incidence of breast cancer in women who are at high risk.